This invention relates to a method of making polycarbonates prepared by the interfacial technique by using 1,1-dimethyl urea compounds as the catalysts.
It is known in the patent literature that in the interfacial polymerization process to make aromatic polycarbonates from dihydric phenols and phosgene the use of small amounts of tertiary amines, quaternary ammonium compounds, phosphorium, arsonium, sulfonium, guanidine, and diamido compounds can be used to catalyze the reaction. Patents which show the foregoing are U.S. Pat. Nos. 3,275,601; 3,185,664; 3,261,810; and 3,763,099.